Actuator

ABSTRACT

The invention is an actuator with simple means for a manual operation in case of emergencies. The invention is an actuator comprising a cylinder ( 100 ) in which the 1 st  fluid pathway ( 103 ) and the 2 nd  fluid pathway ( 104 ) having the different course are formed on the wall ( 110 ) of the cylinder ( 100 ); pistons ( 160 ) positioned in said cylinder ( 100 ) the 1 st  fluid pathway ( 103 ) and the 2 nd  fluid pathway ( 104 ); and the power transmission units ( 120, 130, 140 ) connected to one side of piston ( 160 ), and a pathway ( 210 ) is provided in the cylinder ( 100 ) to communicate the 1 st  space ( 101 ) with the 2 nd  space ( 102 ) in the cylinder ( 100 ), and on one side of the pathway ( 210 ) is provided a hole ( 212 (, to cross the pathway ( 210 ) through which a valve ( 220 ) 9  is engaged to open or close the pathway ( 210 ).

FIELD OF THE INVENTION

The present invention relates to an actuator not only with no separateconverse device for a manual operation in case of emergencies, but alsowith simple structure for saving the manufacturing cost.

BACK GROUND OF THE INVENTION

Generally, the actuator is a device which is coupled to a desired unitand provides a driving part of the unit with a forward or backward forceand/or a rotating force generated by the hydraulic or pneumatic source.The actuator according to the present invention may be applied to bothhydraulic and pneumatic actuators, but for convenience, all descriptionand explanation will be given for the pneumatic actuator, hereinafter.

FIG. 1 depicts an example of actuator according to the prior art, inwhich a pneumatic actuator for operating a swivel valve is shown. Asseen from the drawing, the actuator comprises a pair of piston 160positioned at both side of interior of cylinder 100; a rotating axis 140rotating in either direction by the forward or backward action of piston160; the first air pathway 103 connecting the space 101 between thepistons 160 to the exterior of cylinder; and the second air pathway 104connecting the space 102 between the pistons 160 and the correspondingcylinder end wall to the exterior of cylinder, thereby opening andshutting the valve connected to the rotating axis 140, by each forwardor backward action of the opposed pistons 160, by means of the directionof the compressed air provided through the first and second air pathways103,104.

In this actuator, the pneumatic pipe lines 11,12 which supply thecylinder 100 with the compressed air from the external air compressor 10are provided with the solenoid operated valve 20 for controllingdirection of air flow in order to achieve the selective intake or drainof air. For example, if either the first air path 103 or the second airpath 104 carries out the air intake, the other carries out the airdrain.

Nevertheless, if solenoid operated valve 20 stops operation by power offdue to the service interruption of electric power or for the worker'ssake, the supporting rod 150 linked to the piston 160 must be operatedby manual moving the supporting rod 150 forward or backward in order tomove the solenoid operated valve 20 again. However, under suchsituation, since the solenoid operated valve 20 is placed on the neutralstate, the compressed air in the cylinder 100 can hardly be drained andboth pistons 160 are neither able to move in any direction.

In order to solve the problem, it has been suggested in the prior art toprovide the pneumatic pipe lines 11,12 with a separate converting device30 having a direction controlled ball valve 31 and communicating path32, for promoting the manual operation of actuator. That is, in normaloperating, the communicating path 32 is shut off by the ball valve 31 ofthe converting device 30, and the piston 160 is reciprocated by theaction of solenoid valve 20. On the other hand, when solenoid operatedvalve 20 is powered off, the ball valve 31 is operated to be open, andthe 1st air pathway 103 and the 2nd air pathway 104 in the actuator arecommunicated with each other, so that the pressure of compressed airapplied on the piston 160 may be eliminated.

Therefore, the separate converting device 30 as being aforementioned isessential for the actuator according to the prior art, and itresultantly increases the complication in the structure of the actuatorand causes the increase of manufacturing cost.

SUMMARY OF THE INVETION

The present invention is provided to solve the aforementioned problemsof the prior art, and the object of invention is to provide an actuatornot only with no separate converse device for a manual operation foremergencies, but also with simple structure in order to save themanufacturing cost.

According to one aspect of the invention, an actuator is provided whichcomprising a cylinder 100 in which the 1st fluid pathway 103 and the 2ndfluid pathway 104 having the different course are formed on the wall 110of the cylinder 100 in order for the working fluid to pass through; oneor more piston 160 positioned in said cylinder 100 to divide theinterior space into the 1st space 101 communicating with the exteriorthrough the 1st fluid pathway 103 and the 2nd space 102 communicatingwith the exterior through the 2nd fluid pathway 104, and being movedforward and backward along the length of cylinder 100 by the directionof working fluid supplied through the 1st fluid pathway 103 and the 2ndfluid pathway 104; and the power transmission units 120,130,140connected to one side of piston 160 and transmitting the driving forceof piston 160 to the exterior unit, characterized in that a pathway 210is provided in the cylinder 100 to communicate the 1st space 101 withthe 2nd space 102 in the cylinder 100, and on one side of the pathway210 is provided a hole 212, to cross the pathway 210 through which avalve 220 is engaged to open or close the pathway 210.

According to another aspect of the invention, the both ends of thepathway 210 communicate directly to the 1st fluid pathway 103 and the2nd fluid pathway 104.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a longitudinal section view of actuator according to theprior art;

FIG. 2 shows a longitudinal section view of actuator according to apreferable example of the invention; and

FIG. 3 shows a longitudinal section view of actuator according toanother example of the invention.

For the reader's reference to the drawings, some reference numbers aregiven to the important parts of the devices, as follows:

100: cylinder; 101: the 1st space; 102: the 2nd space; 103: the 1stfluid pathway; 104: the 2nd fluid pathway; 120: rack; 130: pinion; 140:rotating axis 140; 160: piston; 210: communicating pathway; 220: screwvalve

BEST MODE FOR EMBODIMENT OF THE INVENTION

The objects, the features and the advantages of the invention will bedescribed with referring to the drawings. FIG. 2 depicts a longitudinalsection view of actuator according to a preferable example of theinvention. As seen from FIG. 2, the actuator of the invention comprisesa cylinder 100 into which the working fluid is supplied; a pair ofpistons 160 positioned on the opposite sides of cylinder 100; a pair ofracks 120 extending from the piston 160 and moving reciprocally in theopposite direction each other; a pinion 130 fixed on the rotating axis140 on the center of the cylinder 100 to be engaged with the rack 120;the pneumatic pipe lines 11,12 connecting the cylinder 100 to theexternal compressor 10, and a solenoid operated valve 20 placed on thepneumatic pipe lines 11,12 for converting the direction of fluid flow.

According to the preferable example of the invention, the internal spaceof cylinder 100 is partitioned into an inner space 101 (hereinafter, itwill be called as the 1st space) and an outer space 102 (hereinafter, itwill be called as the 2nd space), and the 1st fluid pathway 103 and the2nd fluid pathway 104 are provided in the wall 110 of cylinder 100respectively. Moreover, two pneumatic pipe lines 11,12 connect asolenoid operated valve 20 to each pathway 103,104 by way of nipples107,108 so that when the solenoid operated valve 20 is actuating, thecompressed air from the air compressor 10 is selectively supplied toeither the 1st space or the 2nd space.

Furthermore, on the cylinder wall 110 opposite from the cylinder wallhaving the 1st fluid pathway 103 and the 2nd fluid pathway 104 isprovided a pathway 210 communicating the inner space 101 with the outerspace 102. On one side of the pathway 210, is provided a hole 212 beingexposed to the exterior, in the direction to cross the pathway 210, anda screw valve 220 is installed in the hole 212 in order to open or closethe pathway 210 by the forward movement or backward movement of thescrew valve 220.

The pistons 160 are supported by each supporter rod 150 which extendsfrom each cylinder wall 110 along the longitudinal direction. The racks120 are mounted on the opposing surface of pistons 160 and extendtherefrom so that their toothed sides face to each other. Accordingly,once the piston 160 moves forward or backward, the pinion 130 rotatesclockwise or counterclockwise, so that the rotating axis 140 transmitsthe rotating force from the pinion 130 to the external device such as anexternal valve.

Hereinafter, the action of the actuator according to the invention willbe described in details. In normal state, that is, when the electricpower is applied, the screw valve 220 is engaged into the pathway 210and the pathway 210 is blocked. Then, the 1st space 101 and the 2ndspace 102 in the cylinder 100 are partitioned to be the separated rooms,and the compressed air is selectively supplied by the action of thesolenoid operated valve 20 into the 1st space 101 or the 2nd space 102,thereby effecting an forward or backward movement of the piston 160, bywhich the pinion 130 engaged with the rack 120 will rotate andresultantly transmit rotating force to the external device. For example,if the rotating axis 140 is connected to a swivel valve installed in thepipe network, the open and close action of the swivel valve can beachieved according to the control signal input to the solenoid operatedvalve 20, and the degree of openness of the swivel valve can be adjustedas well.

However, if the electric power to the solenoid operated valve 20 is offdue to the service interruption of electric power or for the worker'ssake, the screw valve 220 may be moved backward to open the pathway 210in order to communicate the 1st space 101 with the 2nd space 102 in thecylinder 100. Then, the air filled in the 1st space 101 and the 2ndspace 102 in the cylinder 100 can flows to each other through thepathway 210. Therefore, the rotating axis 140 can be easily rotated bymeans of manual operation of pulling or pushing the supporter rod 150 asthe air in one space 101,102 can flow to other space 102,101.

According to the present invention, by providing a simple constructionin which a pathway 210 is formed in the cylinder wall 110 and a screwvalve 220 is installed for opening or closing the said pathway 210, theexternal device connected to the said rotating axis 140 can readily beoperated by manual. It may be an advantage of the invention in terms ofsaving the manufacturing costs as well as simplifying the structure ofactuator with no separate converse device for a manual operation of theprior art, which was complicated and expensive.

In the meantime, a preferable mode is given in the example as beingdescribed above only for the easy understanding of invention, in whichthe cylinder 100 has two pistons 160 and the 2nd space 102 has two roomson the opposite side of said cylinder 100, as being communicated eachother. However, the 1st space 101 and the 2nd space 102 in the cylinder100 are merely described to explain the direction of inflow or outflowof working fluid, and their positions and numbers may be changed asvarious as the conventional actuators.

Furthermore, although the rack 120 and pinion 130 are exampled as themeans for transmitting the forward or backward force of the pistons 160to the external driving device, it would be apparent to the ordinaryskilled person in the art that the present invention may be applied tothe general actuator in which the reciprocal linear movement of thepistons 160 may be transmitted to the external device as it is withoutconversion or as being conversed into the rotation force.

Moreover, the pathway 210 as a means for communicating the 1st space 101with the 2nd space 102 in the said cylinder 100 may variously be changedin its position and shape other than the examples described as above. Inother words, as depicted in FIG. 3 according to another example of theinvention, the pathway 210 may be formed to directly connect the 1stfluid pathway 103 and 2nd fluid pathway 104. In this case, the pathway210 can relatively be shortened, and the further advantage may beobtained for the easier manufacture of cylinder 100.

It is not an intention to limit the present invention as describedwithin the aforementioned examples and the drawings attached hereto, andit would be apparent to the ordinary skilled person in the art to whichthe invention belongs, that a various alterations, changes andsubstitutions may be made within the scope and sprit of the invention.

ADVANTAGEOUS EFFECT

According to the present invention as being described above, an actuatoris provided, in which a pathway 210 is formed in the cylinder wall 110,and a screw valve 220 is installed for opening and closing the pathway210, and which has not only no separate converse device for a manualoperation for emergencies, but also the simple structure forsignificantly saving the manufacturing cost.

1. An actuator comprising a cylinder 100 in which the 1st fluid pathway103 and the 2nd fluid pathway 104 having the different course are formedon the wall 110 of the cylinder 100 in order for the working fluid topass through; one or more piston 160 positioned in said cylinder 100 todivide the interior space into the 1st space 101 communicating with theexterior through the 1st fluid pathway 103 and the 2nd space 102communicating with the exterior through the 2nd fluid pathway 104, andbeing moved forward and backward along the length of cylinder 100 by thedirection of working fluid supplied through the 1st fluid pathway 103and the 2nd fluid pathway 104; and the power transmission units120,130,140 connected to one side of piston 160 and transmitting thedriving force of piston 160 to the exterior unit, characterized in thata pathway 210 is provided in the cylinder 100 to communicate the 1stspace 101 with the 2nd space 102 in the cylinder 100, and on one side ofthe pathway 210 is provided a hole 212, to cross the pathway 210 throughwhich a valve 220 is engaged to open or close the pathway
 210. 2. Anactuator of claim 1 wherein, the both ends of the pathway 210communicate directly to the 1st fluid pathway 103 and the 2nd fluidpathway 104.